The best way to initially get an indicator of hedgehog activity in your garden, is to look for their poo!
Hedgehog poo is quite distinctive because of their diet. Each dropping is jam packed full of shiny bits of beetle and other invertebrates and seeds, so it is very textured.
It’s very dark and can vary in size, but is generally the size of the tip of your little finger.
You may have a hedgehog visiting and not even realise! Why not have a scout about the garden to see if you can see any signs!